The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

glabrous above or at first faintly frosted near the apex, white, very fragile. No
evidence of a veil anywhere.
Spores 9-12 x 5-6 p smooth, apical pore present but spore apex not truncate,
shape in face view ovate to broadly elliptic, in profile mostly obscurely inequilateral, color in KOH immediately chocolate-black, in Melzer's dull bay, wall
about 1 / thick.
Basidia 4-spored, clavate, 9-11 pt wide, hyaline in KOH. Brachybasidioles
present. Pleurocystidia and cheilocystidia similar, 40-55 x 6-14 t, utriform, wall
thin, smooth and hyaline, cell content not distinctive. Caulocystidia scattered
and utriform to fusoid-ventricose with obtuse apex, hyaline, thin-walled, content
not distinctive.
Gill trama reddish brown in KOH but fading. Pileus trama of hyphae dull
vinaceous-brown in KOH, the pigment incrusted on the wall and to some extent
the wall itself also colored, fading on standing. Pileus cuticle of a region of
inflated cells 1-2 deep, the wall thin, smooth and yellowish to hyaline, cell content
not distinctive. Clamps present. No distinctive reaction seen on any tissue
mounted in Melzer's.
Type locality. Isle Royale National Park, Michigan.
Habit and habitat. Gregarious on wet earth.
Distribution. Known only from type locality.
Observations. The very dark colored spores when first mounted in KOH, the
utriform to narrowly fusoid-ventricose pleurocystidia, the lack of a veil and the
relatively long slender stipe distinguish P. baileyi. It is to be regarded as close
to P. gracilis but has smaller spores and different cystidia.
268. Psathyrella pinicola A. H. Smith, sp. nov.
Pileus 2-3 cm latus, late convexus, cinnamomeo-brunneus, striatulatus, glaber;
lamellae latae ventricosae confertae griseae; stipes 4-5 cm longus, 3-4 mm crassus,
pallidus, sursum pruinosus, flexuosus; sporae 9-12 x 5-7.5 /; pleurocystidia 34 -60 x 10-18,u, utriformia vel fusoide ventricosa, ad apicerum late rotundata; fibulae
adsunt. Typus. Hesler 15917 (MICH); legit prope Claxton School, Anderson
County, Tennessee.
Illust. Text Figs. 569, 570.
Pileus 2-3 cm broad, convex-expanded, hygrophanous, more or less cinnamonbrown when moist and also striatulate, fading to yellowish ("cartridge buff") or
whitish, margin even or slightly sulcate when faded, no veil remnants evident.
Context thin, concolorous or whitish, odor and taste fungoid.
Lamellae rounded-adnate, ventricose, broad, close, "neutral gray" (lacking a
cinnamon tinge), edge fimbriate.
Stipe 4-5 cm long, 3-4 mm thick, whitish, apex pruinose, naked elsewhere,
flexuous, hollow.
Spores 9-12 x 5-7.5 /, smooth, with a small but distinct apical pore, the spore
apex not being distinctly truncate, shape in face view broadly elliptic, in profile
subelliptic to obscurely inequilateral to obscurely bean-shaped or elliptic, color
in KOH blackish brown and remaining so, in Melzer's bay-brown, wall about
0.5,u thick.
Basidia 18-24x8-12 /, subcapitate, 4-spored. Brachybasidioles 12-14x12 -15 /A, readily collapsing. Pleurocystidia rare to scattered, 34-60x10-18 fL, utriform to fusoid-ventricose with broadly rounded apex, wall thin, smooth and
hyaline, cell content not distinctive. Cheilocystidia similar to pleurocystidia but